1. Technical Field
The invention relates to heat sinks, particularly to fasteners of heat sinks.
2. Related Art
With continuous improvement of semiconductor devices, the requirements to heat sinks also increase. On the other hand, electronic devices also constantly tend to be lighter, thinner, shorter and smaller. Thus heat sinks need not only to further improve to satisfy the requirements of heat dissipation of electronic devices, but also to be lighter and thinner than before.
Taiwan patent No. 1305825 discloses a typical heat sink fastener of the CPU (hereinafter “TW825”). TW 825 uses a heat conductive board attached on the CPU, so the heat conductive plate must exert pressure on the CPU. In TW825, the heat conductive board is fastened by four flexible pins at corners. Each flexible pin is composed of a screw and a spring. The screws must penetrate the heat conductive board and the motherboard so as to fasten the heat conductive board on the motherboard. Thus the screws must possess a specific length. On the other hand, the heat conductive board must be further provided with sleeves for being passed through by the screws. In sum, this kind of structure is relatively complicated and its overall height and weight is hard to be reduced, too. This is very disadvantageous to the thin-and light design of computers.
Taiwan patent No. M276267 discloses another similar heat sink fastener (hereinafter “TW 267”). TW267 differs from TW825 by fixing two extended plates on the heat conductive board. The heat conductive board is fixed on the circuit board by fastening the extended plates on the circuit board. Thus there still are the drawbacks the same as TW825.